Class D amplifiers that each output a PWM signal, which is a signal that has undergone pulse width modulation, and amplify electric power are known (for example, refer to Patent Document 1). The Class D amplifiers include a feedback type and a non-feedback type, and the feedback type, which corrects an error of an output signal, is easy to reduce distortion and can obtain desired output signal characteristics. The class D amplifiers are used for power amplification of an audio signal and the like.